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Poynting Robertson Drag
Poynting may refer to: * John Henry Poynting (1852–1914), a British physicist, after whom are named: ** Poynting vector, a representation of the energy flux of an electromagnetic field ** Poynting's theorem on conservation of energy in electromagnetic field ** Poynting (lunar crater), crater on the Moon ** Poynting (Martian crater) Poynting is an impact crater on Mars. It lies north of Pavonis Mons and west of Ascraeus Mons. It was named by the IAU in 1988 after English astrophysicist John Henry Poynting. Poynting is the largest impact crater in the Tharsis quadrangle ..., crater on Mars ** 11063 Poynting, a main-belt asteroid {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Henry Poynting
John Henry Poynting FRS (9 September 185230 March 1914) was an English physicist. He was the first professor of physics at Mason Science College from 1880 to 1900, and then the successor institution, the University of Birmingham until his death. Biography Poynting was the youngest son of Thomas Elford Poynting, a Unitarian minister. He was born at the parsonage of the Monton Unitarian Chapel in Eccles, Lancashire (his father serving as minister there from 1846 to 1878.) In his boyhood he was educated at the nearby school operated by his father. From 1867 to 1872 he attended Owens College, now the University of Manchester, where his physics teachers included Osborne Reynolds and Balfour Stewart. From 1872 to 1876 he was a student at Cambridge University, where he attained high honours in mathematics after taking grinds with Edward Routh. In the late 1870s he worked in the Cavendish Laboratory at Cambridge under James Clerk Maxwell. In 1880, he became the first professor of phy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poynting Vector
In physics, the Poynting vector (or Umov–Poynting vector) represents the directional energy flux (the energy transfer per unit area per unit time) or ''power flow'' of an electromagnetic field. The SI unit of the Poynting vector is the watt per square metre (W/m2); kg/s3 in base SI units. It is named after its discoverer John Henry Poynting who first derived it in 1884. Nikolay Umov is also credited with formulating the concept. Oliver Heaviside also discovered it independently in the more general form that recognises the freedom of adding the curl of an arbitrary vector field to the definition. The Poynting vector is used throughout electromagnetics in conjunction with Poynting's theorem, the continuity equation expressing conservation of electromagnetic energy, to calculate the power flow in electromagnetic fields. Definition In Poynting's original paper and in most textbooks, the Poynting vector \mathbf is defined as the cross product \mathbf = \mathbf \times \mathb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poynting's Theorem
In electrodynamics, Poynting's theorem is a statement of conservation of energy for electromagnetic fields developed by British physicist John Henry Poynting. It states that in a given volume, the stored energy changes at a rate given by the work done on the charges within the volume, minus the rate at which energy leaves the volume. It is only strictly true in media which is not dispersive, but can be extended for the dispersive case. The theorem is analogous to the work-energy theorem in classical mechanics, and mathematically similar to the continuity equation. Definition Poynting's theorem states that the rate of energy transfer per unit volume from a region of space equals the rate of work done on the charge distribution in the region, plus the energy flux leaving that region. Mathematically: where: * -\frac is the rate of change of the energy density in the volume. * ∇•S is the energy flow out of the volume, given by the divergence of the Poynting vector S. * J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poynting (lunar Crater)
Poynting is a large lunar impact crater located on the far side of the Moon. It is located to the north-northwest of the walled plain Hertzsprung, with the crater Fersman immediately to the east and Kekulé equally near to the west-southwest. This crater has undergone some erosion, and several small craters lie across the rim and inner wall. A pair of these lie next to each other along the eastern side, and another pair on the western rim. Across the southeast rim is a nearly merged crater pair. Parts of the rim remain well-defined, however, including the east and north where there are some terrace Terrace may refer to: Landforms and construction * Fluvial terrace, a natural, flat surface that borders and lies above the floodplain of a stream or river * Terrace, a street suffix * Terrace, the portion of a lot between the public sidewalk an ...s. The rim is generally circular, with a slight inward intrusion along the northwest. The interior floor is relatively level, exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poynting (Martian Crater)
Poynting is an impact crater on Mars. It lies north of Pavonis Mons and west of Ascraeus Mons. It was named by the IAU in 1988 after English astrophysicist John Henry Poynting. Poynting is the largest impact crater in the Tharsis quadrangle The Tharsis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Tharsis quadrangle is also referred to as MC-9 (Mars Chart-9). The name Tharsis ref .... References {{Portal bar, Solar System Impact craters on Mars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
